Technische Verfahren zur Synthese von Carotinoiden und verwandten Verbindungen aus 6??Oxo??isophoron. VII. Synthese von Rhodoxanthin und (3RS, 3RS)?? …
Summary An efficient 7-step synthesis of (3 RS, 3 'RS)-zeaxanthin (3) in 20% overall yield starting from 6-0x0-isophorone (7) is described. Intermediates are 6, 6 '-dihydrorhodoxanthin (4) and rhodoxanthin (l), which are now accessible in 4 and 5 steps, and 45 and 25% overall yield, respectively. Novel methods for the simultaneous removal of the hydroxy group and the partial reduction of the triple bond of a monoalkynylated I, 4-dioxo-2-ene system have ...
